<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title>mobile focus bug demo</title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no">
    <meta name="format-detection" content="telephone=no">
    <style type="text/css">
        html, body, h1, h2, h3, h4, h5, h6, p, ul, li, input, button, textarea {
            margin: 0;
            padding: 0;
        }

        body {
            -webkit-tap-highlight-color: rgba(255, 255, 255, 0);
        }

        html, body {
            -webkit-user-select: none;
            user-select: none;
            overflow-x: hidden;
        }

        body, input, button, textarea {
            font-family: "Helvetica Neue", Helvetica, STHeiTi, sans-serif;
            font-size: 13px;
        }

        input, button, textarea {
            border: none;
            outline: none;
        }

        a, img {
            -webkit-touch-callout: none;
        }

        a {
            text-decoration: none;
            color: #007AFE;
        }

        .box {
            margin: 30px 15px;
            border: 1px solid #DDD;
        }

        .box .labels {
            box-sizing: border-box;
            width: 100%;
            padding: 10px 10px 5px;
            border-bottom: 1px solid #DDD;
            background-color: #DDD;
            display: none;
        }

        .box.active .labels {
            display: block;
        }

        .labels label {
            background-color: #EEE;
            color: #007AFE;
            padding: 3px 8px;
            margin-bottom: 5px;
            display: inline-block;
        }

        .labels .active {
            color: #DDD;
        }

        textarea {
            border: none;
            padding: 10px;
            height: 100px;
            resize: none;
            display: block;
            width: 100%;
            box-sizing: border-box;
        }

        textarea:focus {
            background-color: #FCFCFC;
        }
    </style>
</head>
<body>
    <div id="box" class="box">
        <div class="labels" id="labels">
            <label>green</label>
            <label>black</label>
            <label>blue</label>
            <label>grey</label>
            <label>origin</label>
            <label>yellow</label>
        </div>
        <p>
            <textarea id="ipt"></textarea>
        </p>
    </div>
<script src="http://zeptojs.com/zepto.js"></script>
<script type="text/javascript">
;(function($){
  var touch = {},
    touchTimeout, tapTimeout, swipeTimeout, longTapTimeout,
    longTapDelay = 750,
    gesture

  function swipeDirection(x1, x2, y1, y2) {
    return Math.abs(x1 - x2) >=
      Math.abs(y1 - y2) ? (x1 - x2 > 0 ? 'Left' : 'Right') : (y1 - y2 > 0 ? 'Up' : 'Down')
  }

  function longTap() {
    longTapTimeout = null
    if (touch.last) {
      touch.el.trigger('longTap')
      touch = {}
    }
  }

  function cancelLongTap() {
    if (longTapTimeout) clearTimeout(longTapTimeout)
    longTapTimeout = null
  }

  function cancelAll() {
    if (touchTimeout) clearTimeout(touchTimeout)
    if (tapTimeout) clearTimeout(tapTimeout)
    if (swipeTimeout) clearTimeout(swipeTimeout)
    if (longTapTimeout) clearTimeout(longTapTimeout)
    touchTimeout = tapTimeout = swipeTimeout = longTapTimeout = null
    touch = {}
  }

  function isPrimaryTouch(event){
    return (event.pointerType == 'touch' ||
      event.pointerType == event.MSPOINTER_TYPE_TOUCH)
      && event.isPrimary
  }

  function isPointerEventType(e, type){
    return (e.type == 'pointer'+type ||
      e.type.toLowerCase() == 'mspointer'+type)
  }

  $(document).ready(function(){
    var now, delta, deltaX = 0, deltaY = 0, firstTouch, _isPointerType

    if ('MSGesture' in window) {
      gesture = new MSGesture()
      gesture.target = document.body
    }

    $(document)
      .bind('MSGestureEnd', function(e){
        var swipeDirectionFromVelocity =
          e.velocityX > 1 ? 'Right' : e.velocityX < -1 ? 'Left' : e.velocityY > 1 ? 'Down' : e.velocityY < -1 ? 'Up' : null;
        if (swipeDirectionFromVelocity) {
          touch.el.trigger('swipe')
          touch.el.trigger('swipe'+ swipeDirectionFromVelocity)
        }
      })
      .on('touchstart MSPointerDown pointerdown', function(e){
        if((_isPointerType = isPointerEventType(e, 'down')) &&
          !isPrimaryTouch(e)) return
        firstTouch = _isPointerType ? e : e.touches[0]
        if (e.touches && e.touches.length === 1 && touch.x2) {
          // Clear out touch movement data if we have it sticking around
          // This can occur if touchcancel doesn't fire due to preventDefault, etc.
          touch.x2 = undefined
          touch.y2 = undefined
        }
        now = Date.now()
        delta = now - (touch.last || now)
        touch.el = $('tagName' in firstTouch.target ?
          firstTouch.target : firstTouch.target.parentNode)
        touchTimeout && clearTimeout(touchTimeout)
        touch.x1 = firstTouch.pageX
        touch.y1 = firstTouch.pageY
        if (delta > 0 && delta <= 250) touch.isDoubleTap = true
        touch.last = now
        longTapTimeout = setTimeout(longTap, longTapDelay)
        // adds the current touch contact for IE gesture recognition
        if (gesture && _isPointerType) gesture.addPointer(e.pointerId);
      })
      .on('touchmove MSPointerMove pointermove', function(e){
        if((_isPointerType = isPointerEventType(e, 'move')) &&
          !isPrimaryTouch(e)) return
        firstTouch = _isPointerType ? e : e.touches[0]
        cancelLongTap()
        touch.x2 = firstTouch.pageX
        touch.y2 = firstTouch.pageY

        deltaX += Math.abs(touch.x1 - touch.x2)
        deltaY += Math.abs(touch.y1 - touch.y2)
      })
      .on('touchend MSPointerUp pointerup', function(e){
        if((_isPointerType = isPointerEventType(e, 'up')) &&
          !isPrimaryTouch(e)) return
        cancelLongTap()

        // swipe
        if ((touch.x2 && Math.abs(touch.x1 - touch.x2) > 30) ||
            (touch.y2 && Math.abs(touch.y1 - touch.y2) > 30))

          swipeTimeout = setTimeout(function() {
            touch.el.trigger('swipe')
            touch.el.trigger('swipe' + (swipeDirection(touch.x1, touch.x2, touch.y1, touch.y2)))
            touch = {}
          }, 0)

        // normal tap
        else if ('last' in touch)
          // don't fire tap when delta position changed by more than 30 pixels,
          // for instance when moving to a point and back to origin
          if (deltaX < 30 && deltaY < 30) {
            // delay by one tick so we can cancel the 'tap' event if 'scroll' fires
            // ('tap' fires before 'scroll')
            tapTimeout = setTimeout(function() {

              // trigger universal 'tap' with the option to cancelTouch()
              // (cancelTouch cancels processing of single vs double taps for faster 'tap' response)
              var event = $.Event('tap')
              event.cancelTouch = cancelAll
              touch.el.trigger(event)

              // trigger double tap immediately
              if (touch.isDoubleTap) {
                if (touch.el) touch.el.trigger('doubleTap')
                touch = {}
              }

              // trigger single tap after 250ms of inactivity
              else {
                touchTimeout = setTimeout(function(){
                  touchTimeout = null
                  if (touch.el) touch.el.trigger('singleTap')
                  touch = {}
                }, 250)
              }
            }, 0)
          } else {
            touch = {}
          }
          deltaX = deltaY = 0

      })
      // when the browser window loses focus,
      // for example when a modal dialog is shown,
      // cancel all ongoing events
      .on('touchcancel MSPointerCancel pointercancel', cancelAll)

    // scrolling the window indicates intention of the user
    // to scroll, not tap or swipe, so cancel all ongoing events
    $(window).on('scroll', cancelAll)
  })

  ;['swipe', 'swipeLeft', 'swipeRight', 'swipeUp', 'swipeDown',
    'doubleTap', 'tap', 'singleTap', 'longTap'].forEach(function(eventName){
    $.fn[eventName] = function(callback){ return this.on(eventName, callback) }
  })
})(Zepto);
</script>
<script type="text/javascript">
$(document).ready(function() {
    var $box = $('#box');
    var $ipt = $('#ipt');
    var isFocus = false;

    $('#labels').on('tap', function(e) {
        var target = e.target;
        var tag = target.nodeName.toLowerCase();
        var cls = target.classList;

        if(tag && tag === 'label') {
            // e.preventDeafult();
            e.stopPropagation();
            isFocus = true;
            $ipt.focus()

            if(!cls.contains('active')) {
                // isFocus = true;
                $ipt.val($ipt.val() + target.innerHTML).focus();
                cls.add('active');
            }

            return;
        }
    });

    $ipt
        .on('tap', function(e) {
            e.stopPropagation();
        })
        .on('focus', function() {
            if(!isFocus) {
                isFocus = true;
                $box.addClass('active');
            }
        });

    $(document).on('tap', function() {
        if(!isFocus) return;
        isFocus = false;
        $box.removeClass('active');
        $ipt.blur();
    });
});
</script>
</body>
</html>
